What is SDS Syndrome

Shwachman–Diamond syndrome (SDS) is a rare autosomal recessive disorder first described in 1964. The predominant manifestations of the syndrome include exocrine pancreatic insufficiency, bone marrow failure and skeletal abnormalities. Patients frequently present failure to thrive, susceptibility to infections and short stature.

Pancreas insufficiency is present in the first days of birth. During childhood, almost 50% of patients present spontaneous improvement in pancreatic function, discontinuing pancreatic enzyme supplements.

A persistent or intermittent neutropenia occurs in 88–100% of patients. Bone marrow biopsy usually reveals a hypoplastic specimen with varying degrees of hypoplasia and fat infiltration. Some patients may develop myeloblastic syndrome and acute myeloblastic leukemia.

In 2002, researchers from Toronto identified the gene (SBDS) that is altered in SDS on chromosome 7q11.
The SBDS is expressed ubiquitously in all mammalian tissue, and other organs can be involved such as teeth and oral cavity, liver, heart, kidneys and skin.

An alteration in learning and behavioral profile is also described. Deficits in cognitive abilities are present in the majority of individuals with SDS at different levels of impairment showing a heterogeneous involvement.

In spite of new SBDS mutations identified in later years, until now up to 10% of patients with clinical features of SDS lack SBDS mutations. The negative gene test does not, however, exclude the diagnosis, and an accurate evaluation of clinical signs is compulsory to diagnose the presence of the syndrome.